FIELD OF THE INVENTION
[0001] The invention relates to an apparatus for scanning an object of interest with an
X-ray beam, particularly to a system for generating and collimating an X-ray beam.
BACKGROUND OF THE INVENTION
[0002] X-ray imaging devices are used to obtain information about internal structures within
an object of interest by irradiating the object with an X-ray beam generated by an
X-ray source. For example, in medical X-ray imaging, those devices are used to obtain
information about the inside structures (bones, organs...) within a human body. An
X-ray imaging device can acquire two-dimensional or three-dimensional images. For
example, an X-ray imaging device can be a conventional X-ray imaging device for acquiring
two-dimensional X-ray projection images, a C-arm X-ray imaging device, or a computer
tomography (CT) device.
[0003] Conventionally, an X-ray source, often called X-ray tube, comprises a tube housing
and an X-ray tube insert inside the tube housing. The X-ray tube insert is a vacuum
tube, and comprises a so-called tube insert cap for sealing the tube. Inside the tube
insert cap, there are a cathode for emitting electrons and an anode for emitting X-ray
beam upon receiving the electrons. The tube housing protects the fragile vacuum tube.
Typically, the tube housing is opaque to X-ray radiation and has an opening for allowing
the X-ray beam to pass through. The emitted X-ray beam is directed towards a region
of interest, for example a part of the patient's body. Since different tissues and/or
bones within the patient's body have different levels of X-ray absorption, the X ray
beam having passed through the region of interest is attenuated accordingly. The X
ray beam having passed through the region of interest is then detected by an X-ray
detector and the signal indicative of detected X-ray intensities, and the detected
signal contains information about the internal structure within the patient's body
and such information is retrieved, e.g. by forming X-ray images, accordingly.
[0004] A collimator can be used to collimate the X-ray beam generated by the X-ray source
to be a slice of the X-ray beam passing through the region of interest. The collimator
can be used to provide collimation for the X-ray beam so as to limit the size of the
X-ray beam after passing through the collimator. For example, in typical CT systems,
collimation is achieved by a blade set comprising of two moveable blades and a moveable
plate with fixed slots or cams.
US2015/0173692A1 discloses a device including a radiation source to emit radiation from a focal spot
toward a volume of interest and a dynamic collimator located between the focal spot
and the volume of interest.
[0005] WO2012/058207A2 discloses an X-ray beam scanner comprising an X-ray source and a collimator, which
is stationary during image scanning, for collimating the X-ray beam so as to change
the extent of the scan. The collimator is a standalone unit and is located outside
the x-ray source, namely outside the tube housing which has an opening thereon. The
inventor has recognized that such X-ray source and collimator as a whole are complex
in structure.
[0006] US2013/0294582A1 discloses an X-ray imaging apparatus with a multi X-ray source and a collimator in
which a plurality of slits for X-rays to pass through are two-dimensionally formed,
the size and position of the slits being adjustable.
[0007] US5384820 discloses an x-ray tube assembly comprising a housing, an x-ray tube and a cylindrical
sleeve.
[0008] US2012/0106714A1 discloses an apparatus for interrupting and/or scanning a beam of penetrating radiation,
such as for purposes of inspecting contents of a container.
OBJECT AND SUMMARY OF THE INVENTION
[0009] Therefore, it is advantageous to provide a system for generating and collimating
an X-ray beam which mitigates and/or alleviates the above-mentioned problems.
[0010] According to a first aspect of the present invention, there is provided a system
for generating and collimating an X-ray beam. The system comprises: an X-ray tube
insert for generating said X-ray beam, said X-ray tube insert being a vacuum tube;
a tube housing for containing said X-ray tube insert, said tube housing being made
of an X-ray absorbing material; and a collimator for collimating said X-ray beam;
wherein said collimator is arranged between said X-ray tube insert and said tube housing.
By having the collimator arranged in between the X-ray tube insert and the tube housing,
it is not required to have additional space outside the tube housing. In this way,
the system can be made much more compact in terms of weight and/or size. Consequently,
the implementation in an apparatus of smaller size may be facilitated, and costs may
be reduced.
[0011] In an embodiment of the system according to the present invention, the collimator
comprises a plurality of collimating areas, and the collimator is adapted to be movable
with respect to the tube insert so as to select one of the plurality of collimating
areas for collimating the X-ray beam.
A selected one of the collimating areas is allowed to be moved in a position to collimate
the X-ray beam. The multiple collimating areas enable multiple choices of collimation
for the X-ray beam.
[0012] In another embodiment of the system according to the present invention, the plurality
of collimating areas can be different in size and/or shape. Preferably, each of at
least one collimating area is a slit.
The various size and/or shape of the slits forming the collimating areas allow multiple
choices for collimation. As regards the size of the X-ray beam, multiple choices are
possible after it has passed through a slit of a different size.
[0013] In an embodiment, each of at least one of the collimating areas is a completely material-free
opening. In other words, the collimating area is a complete opening.
In another embodiment, each of at least one of the plurality of collimating areas
comprises a plurality of pinholes.
In another embodiment, each of at least one collimating areas comprises a plurality
of slots.
[0014] In another embodiment of the system according to the present invention, the collimator
is adapted to rotate about an axis so as to select one of the collimating areas for
collimating the X-ray beam, wherein the axis is perpendicular to an irradiation direction
of the X-ray beam.
In an embodiment, said plurality of collimating areas is displaced at the same position
along the axis perpendicular to an irradiation direction of the X-ray beam.
Rotating the collimator allows placing a given collimating area in front of the X-ray
beam.
[0015] In another embodiment of the system according to the present invention, the collimator
is adapted to translate along an axis so as to select one of the collimating areas
for collimating the X-ray beam, wherein the axis is perpendicular to an irradiation
direction of the X-ray beam. For example, the axis can be a central axis of the X-ray
tube insert.
In an embodiment, at least two of said plurality of collimating areas are displaced
at different position along the axis perpendicular to an irradiation direction of
the X-ray beam.
Translating the collimator allows placing one of the collimating areas to the propagating
path of the X-ray beam.
[0016] In another embodiment of the system according to the present invention, the system
further comprises an actuator for controlling the movement of the collimator.
The actuator allows the collimator to make rotating and/or translating movements along
the central axis.
[0017] In another embodiment of the system according to the present invention, the collimator
comprises a cylinder-shape portion and the plurality of collimating areas are arranged
at a circumference surface of the cylinder-shaped portion of the collimator. For example,
the collimating areas extends around the longitudinal axis of the cylinder-shaped
collimator.
[0018] According to a second aspect of the present invention, an apparatus for scanning
an object of interest with an X-ray beam is provided. The apparatus comprises: a system
for generating and collimating the X-ray beam, and a detector for detecting the X-ray
beam after the X-ray beam has passed through the object of interest.
[0019] Detailed explanations and other aspects of the invention will be given below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Particular aspects of the invention will now be explained with reference to the embodiments
described hereinafter and considered in connection with the accompanying drawings,
in which identical parts or sub-steps are designated in the same manner:
Fig.1 depicts the longitudinal cross-sectional view of a system for generating and
collimating an X-ray beam in accordance with an embodiment of the present invention;
Each of Fig.2A and Fig.2B depicts the transverse cross-sectional view of a system
for generating and collimating an X-ray beam in accordance with an embodiment of the
present invention so as to illustration the connections between the elements of the
system;
Fig.3 depicts a three-dimensional view of an exemplary collimator in accordance with
an embodiment of the present invention;
Each of Fig.4A, Fig.4B and Fig.4C depicts an exemplary collimating area of a collimator
in accordance with an embodiment of the present invention;
Each of Fig.5A and Fig.5B depicts an exemplary collimator in accordance with an embodiment
of the present invention; and
Fig.6 depicts a schematic design of an apparatus for scanning an object of interest
with an X-ray in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Fig.1 depicts the longitudinal cross-sectional view of a system 100 for generating
and collimating an X-ray beam in accordance with an embodiment of the present invention.
The system 100 comprises an X-ray tube insert 101, a tube housing 102 for containing
the X-ray tube insert 101, and a collimator 103. The X-ray tube insert 101 is a vacuum
tube. A so-called tube insert cap is configured to seal the tube to provide the vacuum
environment. Inside the tube insert cap, there are a cathode for emitting electrons
and an anode for emitting X-ray beam upon receiving the electrons.
[0022] An X-ray beam 104 is generated by the X-ray tube insert 101. The tube housing 102
surrounds the X-ray tube insert 101. A collimator 103 is placed outside the X-ray
tube insert 101 and inside the tube housing 102.
[0023] In an embodiment as illustrated in Fig.1, the tube insert 101 comprises a cylinder-shaped
portion, and the collimator 103 also comprises a cylinder-shaped portion and is arranged
surrounding the cylinder-shaped potion of the tube insert 102.
[0024] The collimator 103 is mounted to either the outer surface of the X-ray tube insert
101, i.e. the outer surface of the tube insert cap, or the collimator 103 is mounted
to the inner surface of the tube housing 102.
For example, bearings are used to mount the collimator 103. The collimator 103 is
mounted to one race of a bearing, and another race of the bearing is attached to either
the outer surface of the X-ray tube insert 101 as illustrated in Fig.2A or the inner
surface of the tube housing 102 as illustrated in Fig.2B. In another embodiment, the
collimator 103 is made part of the race of the bearing. For example, the collimator
103 is the outer race of the bearing or inner race of the bearing.
[0025] The collimator 103 comprises at least one collimating area for collimating the X-ray
beam. The X-ray beam 104 passes through the collimating area of the collimator 103
and then the tube housing 102, particularly an opening of the tube housing 102.
[0026] In some embodiments, the collimator 103 is made of X-ray absorbing material, for
example, lead, tungsten, and an alloy thereof. Typically, the collimating area is
an opening, such as a slit, of the collimator so as to allow the X-ray beam 104 to
pass through.
[0027] Advantageously, the collimator 103 comprises a plurality of collimating areas 106,
wherein the collimator 103 is adapted to be movable with respect to the tube insert
so as to bring a selected one of the collimating areas into the X-ray beam for collimating
the X-ray beam.
[0028] Fig.3 depicts a three-dimensional view of a collimator in accordance with an embodiment
of the present invention.
[0029] There are a plurality of collimating areas 106 on the collimator 103. During X-ray
beam collimation, one of the plurality of collimating areas 106 is selected to be
placed in the X-ray beam. The selected one of the plurality of collimating areas 106
is adapted to be moved to a specific position.
[0030] For example, if the X-ray beam is generated during CT (Computed Tomography) scanning,
the size of the X-ray beam to be applied to the object of interest may be different.
In order to cover the object of interest and avoid an unnecessary dose, a suitable
size of the X-ray beam to be applied to the object of interest must be collimated.
A plurality of collimating areas 106 allows multiple options for collimation. Meanwhile,
selecting one of the plurality of collimating areas 106 is necessary for X-ray beam
collimation for the specific object of interest.
[0031] Referring to the Fig.3, the collimating area 106 can be a slit. Different collimating
area 106 can be of different shape and/or size so as to collimate the X-ray beam into
a different shape and/or size.
[0032] The collimating area, such as a slit, can be completely material-free, or comprises
multiple openings. Each of Fig.4A, Fig.4B and Fig.4C depict an exemplary collimating
area in accordance with an embodiment of the present invention.
[0033] As illustrated in Fig.4A, an example of the collimating area is a slit 110, which
is completely material-free.
[0034] The collimator 103 comprises at least one collimating area. Accordingly, the collimator
103 comprises at least one open slit, each forming one collimating area.
[0035] Referring back to Fig.3, in an embodiment, the collimator 103 is of a circular cylinder
in shape, and each slit extends around the central axis AA, namely the longitudinal
axis of the cylinder. The size of the at least one slit can be different from each
other. In particular, the width of one slit, namely the dimension along the direction
parallel to the central axis AA, and/or the length of the slit, namely the dimension
the list extends, can be different.
[0036] With the slit 110, the X-ray radiation beam 104 is collimated to a fan-shaped beam.
The width and the length of the slit 110 define the thickness and the fan angle of
the collimated X-ray beam 104.
The thickness of the collimated X-ray beam 104 is dependent on the width of the slit
110. The wider the slit 110, the thicker the collimated X-ray beam 104 is. The fan
angle of the collimated X-ray beam 104 is dependent on the length of the slit 110.
The longer the length of the slit 110, the larger the fan angle is of the collimated
X-ray beam 104.
The length of the slit 110 along the circumference of the collimator 103 depends on
the diameter of the X-ray tube insert 101 and the number of slits. For example, the
slit 110 has a length up to a few hundred millimetres for a CT scan.
The width of the slit 110 depends on a specific system design requirement. For example,
the width of the slit 110 relates to a slice thickness for a CT scan. For example,
the slit 110 has a width up to a few tens of millimetres.
[0037] In some embodiments, instead of being a complete opening, namely completely material-free,
the collimating area can be "binary opening" be made of a series small slots or hols.
Such "binary opening" is advantageous in reducing issues with scattered radiation
which occur when the collimator is located very close to the focal point of the anode
disk.
[0038] As illustrated in Fig.4B, another example collimating area is not completely material-free,
but comprises a plurality of pinholes 111.
[0039] For example, the lateral dimensions of a given collimating area range between a few
centimetres and a few tens of centimetres. For example, the number of pinholes 111
is more than 100, preferably more than 1000. The pinholes may be provided in a regular
pattern or irregularly, for example randomly distributed.
[0040] As illustrated in Fig.4C, another example collimating area is not completely material-free,
but comprises a plurality of slots 109 extending along the width direction of the
collimating area.
[0041] Referring back to Fig.3, the collimator 103 is adapted to rotate about the axis AA,
and the collimator 103 is so mounted to the X-ray tube insert that the X-ray beam
is irradiated along a direction perpendicular to the central axis AA. In an embodiment,
the axis AA is the central axis AA of the X-ray tube insert 101.
[0042] Further, the collimator 103 comprises a plurality of collimating areas 106, each
extending around the central axis AA and being adjacent to each other. By rotating
the collimator 103, one collimating area of the plurality of collimating areas 106
is moved so as to be in the X-ray beam 104 and thus be selected to collimate the X-ray
beam 104.
[0043] The rotation of the collimator 103 enables any one of the plurality of collimating
areas 106 to be moved into the X-ray beam 104. During the rotation, the step of the
rotation angle of the collimator 103 is defined by an angular position difference
of the plurality of collimating areas 106. For example, for a collimator with five
slits, the angular position difference is 72 degrees (360/5 = 72), hence the step
of the rotation angle is 72 degrees.
[0044] Alternatively or additionally, the collimator 103 is adapted to translate along the
axis AA.
By translating the collimator 103 along a central axis AA, one collimating area of
the plurality of collimating areas 106 is moved to be in the X-ray beam 104.
For example, the translation of the collimator 103 is enabled by thread transmission.
The thread is on the collimator 103 and the X-ray tube insert 101, or the thread is
on the collimator 103 and the tube housing 102.
[0045] The translation range of the collimator 103 relates to the available space inside
the tube housing 102. The total required width of the plurality of collimating areas
106 and the conjunction material length in between together defines the total translation
distance of the collimator 103.
[0046] Each of Fig.5A and Fig.5B depicts an exemplary collimator in accordance with an embodiment
of the present invention.
In an embodiment as illustrated in Fig.5A, the collimator is cylinder in shape and
has a central axis AA. A plurality of collimating areas, such as a plurality of slits
110 are located at the same position along the central axis AA. For example, the slits
110 comprise a symmetry axis in a same plane perpendicular to the central axis AA.
Various slits which comprising a symmetry axis in a same plane perpendicular to the
central axis allow placing one of the selected slits in front of the X-ray radiation
beam, by rotating the collimator.
The direction of the symmetry axis of the slits 110 is along the circumference of
the collimator 103.
[0047] Fig.5A illustrates an example of the slits 110 in accordance with this embodiment.
For example, the number of slits 110 can be five.
[0048] More generally, the number of collimating areas 106 depends on the range of the X-ray
beam collimation system. For example, for a low-end X-ray beam collimation system,
two collimating areas may be used to provide two options for collimation.
[0049] However, to meet most systems requirements, a number of five collimating areas is
a good compromise between flexibility and practical use.
The larger the number of collimating areas, the more collimation options there are
to choose from. On the other hand, the larger the number of collimating areas, the
smaller the size of the collimating areas is, which means the smaller the size of
the X-ray beam after passing through the collimator 103.
For example, a CT collimation requires a fan beam angle to be 50-60 degrees in front
view. With five collimating areas regularly spaced over a circular ring, the fan beam
angle is around 72 degrees if the symmetry axis of all five slits is a same plane
perpendicular to the central axis AA.
[0050] In another embodiment as illustrated in Fig.5B, the plurality of collimating areas,
such as the plurality of slits 110 extending around the axis AA and displaced at a
different position along the axis AA. For example, the slits 110 comprise a symmetry
axis at different parallel planes perpendicular to the axis AA. Various slits comprising
a symmetry axis in different parallel planes perpendicular to the central axis allow
placing one of the selected slits in front of the X-ray beam by rotating and translating
the collimator.
[0051] Fig.5B illustrates an example of the slits 110 in accordance with this embodiment.
[0052] In a preferable embodiment of the system, the movement of the collimator 103 comprises
both rotation around the axis AA and translation along the axis AA at the same time.
In a practical embodiment, the length along the circumference of a slit of the slits
110 may be at least equal to a half-length of the circumference of the collimator
103. Therefore, the length along the circumference of a slit of the slits 110 is long
enough to cover the specific collimating area when rotated to the specific collimating
area.
[0053] In some embodiments, the pinholes 111 have a density at a center region 107 of the
at least one of the collimating areas which is higher than at border regions 108 of
the at least one of the collimating areas.
The density of the pinholes is higher at a center region 107 than at border regions
108, such that the transparency to the X-ray beam 104 is higher at the center region
107 than at border regions 108. Therefore, the intensity of the X-ray beam 104 after
passing through the pinholes is higher at the center region 107 than at border regions
108.
For example, in a CT scan, the X-ray beam is emitted towards a part of a human body.
The human body is thicker at a center region of the human body than at border regions
of the human body. Therefore, the necessary X-ray beam intensity is more important
at the center region of the human body than at the border regions of the human body.
[0054] In some embodiments, in at least one of the collimating areas, the slots 109 are
arranged parallel to each other along a direction transverse with respect to the axial
direction of the at least one of the collimating areas, and are separated from each
other by a plurality of X-ray absorbing regions, the width of the slots 111 at a center
region 112 of the at least one of the collimating areas being larger than at border
regions 113 of the at least one of the collimating areas.
[0055] The width of the slots is larger at a center region 112 than at border regions 113,
such that the transparency to the X-ray beam 104 is higher at the center region 112
than at border regions 113. Therefore, the intensity of the X-ray beam 104 after passing
through the slots is higher at the center region 112 than at border regions 113.
[0056] In some embodiments, in the system 100, the collimator 103 is cylinder-shaped.
As illustrated in Fig.3, the collimator 103 is cylinder-shaped, or in other words,
of a cylindrical shape, which is the same shape as a portion of the X-ray tube insert
101 and/or the tube housing 102 where it is mounted.
[0057] In some embodiments, the system 100 may further comprise an actuator 301 (not shown)
for controlling the movement of the collimator 103.
The actuator 301 is connected to the collimator 103. The movement of the collimator
103, including rotation along the central axis and translation along the central axis,
is controlled by the actuator 301.
For example, the actuator 301 corresponds to a step motor or a servo motor.
[0058] Fig. 6 depicts a schematic design of an apparatus 200 for scanning an object of interest
201 with an X-ray beam 104 in accordance with an embodiment of the present invention.
The apparatus 200 comprises a system for generating and collimating an X-ray beam
104, and a detector 202 for detecting the X-ray beam 104 after the X-ray beam has
passed through the object of interest 201. The apparatus 200 can further comprise
a processor for generating an image on basis of a signal indicative of the intensity
of the X-ray beam 104 detected by the detector 202.
[0059] A support 203 is used for supporting the object of interest 201. The support 203
is placed between the system 100 and the detector 202. A console (not shown) connects
to the detector 202. The console can process the signal received from the detector
202 and visualiz the signal on a display.
The detector 202 detects the X-ray radiation beam after the beam has passed through
the object of interest 201 and the support 203, and generates an image accordingly.
The generated image is sent to the console and visualized on a display subsequently.
[0060] The above embodiments as described are only illustrative, and not intended to limit
the technique approaches of the present invention. Although the present invention
is described in details referring to the preferable embodiments, those skilled in
the art will understand that the technique approaches of the present invention can
be modified or equally displaced without departing from the scope of the technique
approaches of the present invention, which will also fall into the protective scope
of the claims of the present invention. In the claims, the word "comprising" does
not exclude other elements or steps, and the indefinite article "a" or "an" does not
exclude a plurality. Any reference signs in the claims should not be construed as
limiting the scope.
1. A system (100) for generating and collimating an X-ray beam (104), comprising:
an X-ray tube insert (101) for generating said X-ray beam, said X-ray tube insert
(101) being a vacuum tube;
a tube housing (102) for containing said X-ray tube insert (101), said tube housing
(102) being made of an X-ray absorbing material; and
a collimator (103) for collimating said X-ray beam (104);
wherein said collimator (103) is arranged between said X-ray tube insert (101) and
said tube housing (102).
wherein said collimator (103) comprises a plurality of collimating areas (106), and
wherein said collimator (103) is adapted to be movable with respect to the X-ray tube
insert (101) so as to select one of the plurality of collimating areas (106) for collimating
the X-ray beam,
characterised in that each of at least one of the plurality of collimating areas (106) comprises a plurality
of binary openings (109,111), wherein said binary openings (109,111) have a density
in a center region (107) of a collimating area being higher than at border regions
(108) of the collimating area.
2. A system as claimed in claim 1, wherein each of at least one of the collimating areas
(106) is a completely material-free opening.
3. A system as claimed in claim 1, wherein each of at least one of the plurality of collimating
areas (106) comprises a plurality of pinholes (111).
4. A system as claimed in claim3, wherein said pinholes (111) have a density in a center
region (107) of a collimating area being higher than at border regions (108) of the
collimating area.
5. A system as claimed in claim 1, wherein each of at least one of the plurality collimating
areas (106) comprises a plurality of slots (109).
6. A system as claimed in claim 5, wherein the width of said slots (109) at a center
region (112) of a collimating area is larger than at border regions (113) of the collimating
area.
7. A system as claimed in claim 1, wherein said collimator (103) is adapted to rotate
around an axis (AA) so as to select one of the collimating areas for collimating the
X-ray beam (104), the axis (AA) is perpendicular to an irradiation direction of the
X-ray beam (104).
8. A system as claimed in claim 7, wherein said plurality of said collimating areas (106)
are displaced at the same position along the axis (AA).
9. A system as claimed in claim 1, wherein said collimator (103) is adapted to translate
along an axis (AA) of said X-ray tube insert (101) so as to select one of the collimating
areas for collimating the X-ray beam (104), the axis (AA) is perpendicular to an irradiation
direction of the X-ray beam (104).
10. A system as claimed in claim 9, wherein at least two of said plurality of said collimator
(103) are displaced at a different position along the axis (AA).
11. A system as claimed in claim 1, wherein the tube insert (101) comprises a cylinder-shaped
portion, and the collimator (103) comprises a cylinder-shaped portion and is arranged
surrounding the cylinder shaped portion of the tube insert (101).
12. A system as claimed in claim 1, wherein said collimator (103) comprises a cylinder-shaped
portion and the plurality of collimating areas are arranged at a circumference surface
of cylinder-shaped portion of the collimator (103).
13. A system as claimed in claim 1, further comprising:
an actuator (301) for driving the movement of said collimator (103).
14. An apparatus (200) for scanning an object of interest (201) with an X-ray beam (104),
said apparatus (200) comprising:
a system for generating and collimating the X-ray beam as claimed in any one of claims
1 to 13; and
a detector (202) for detecting said X-ray beam (104) after said X-ray beam has passed
through the object of interest (201).
1. System (100) zum Erzeugen und Kollimieren eines Röntgenstrahls (104), umfassend:
einen Röntgenröhreneinsatz (101) zum Erzeugen des Röntgenstrahls, wobei der Röntgenröhreneinsatz
(101) eine Vakuumröhre ist;
ein Röhrengehäuse (102) zum Enthalten des Röntgenröhreneinsatzes (101), wobei das
Röhrengehäuse (102) aus einem röntgenabsorbierenden Material hergestellt ist; und
einen Kollimator (103) zum Kollimieren des Röntgenstrahls (104);
wobei der Kollimator (103) zwischen dem Röntgenröhreneinsatz (101) und dem Röhrengehäuse
(102) angeordnet ist.
wobei der Kollimator (103) eine Vielzahl von Kollimierbereichen (106) umfasst und
wobei der Kollimator (103) angepasst ist, um in Bezug auf den Röntgenröhreneinsatz
(101) bewegbar zu sein, um einen der Vielzahl von Kollimierbereichen (106) zum Kollimieren
des Röntgenstrahls auszuwählen,
dadurch gekennzeichnet, dass
jeder des mindestens einen der Vielzahl von Kollimierbereichen (106) eine Vielzahl
von binären Öffnungen (109,111) umfasst, wobei die binären Öffnungen (109,111) eine
Dichte in einer Zentralregion (107) eines Kollimierbereichs aufweisen, die höher ist
als in Randregionen (108) des Kollimierbereichs.
2. System nach Anspruch 1, wobei jeder des mindestens einen der Kollimierbereiche (106)
eine vollständig materialfreie Öffnung ist.
3. System nach Anspruch 1, wobei jeder des mindestens einen der Vielzahl von Kollimierbereichen
(106) eine Vielzahl von Lochblenden (111) umfasst.
4. System nach Anspruch 3, wobei die Lochblenden (111) eine Dichte in einer Zentralregion
(107) eines Kollimierbereichs aufweisen, die höher ist als in Randregionen (108) des
Kollimierbereichs.
5. System nach Anspruch 1, wobei jeder des mindestens einen der Vielzahl von Kollimierbereichen
(106) eine Vielzahl von Schlitzen (109) umfasst.
6. System nach Anspruch 5, wobei die Breite der Schlitze (109) in einer Zentralregion
(112) eines Kollimierbereichs größer ist als in Randregionen (113) des Kollimierbereichs.
7. System nach Anspruch 1, wobei der Kollimator (103) angepasst ist, um sich um eine
Achse (AA) zu drehen, um einen der Kollimierbereiche zum Kollimieren des Röntgenstrahls
(104) auszuwählen, wobei die Achse (AA) senkrecht zu einer Bestrahlungsrichtung des
Röntgenstrahls (104) ist.
8. System nach Anspruch 7, wobei die Vielzahl der Kollimierbereiche (106) an der gleichen
Position entlang der Achse (AA) versetzt ist.
9. System nach Anspruch 1, wobei der Kollimator (103) angepasst ist, um sich entlang
einer Achse (AA) des Röntgenröhreneinsatzes (101) zu verschieben, um einen der Kollimierbereiche
zum Kollimieren des Röntgenstrahls (104) auszuwählen, wobei die Achse (AA) senkrecht
zu einer Bestrahlungsrichtung des Röntgenstrahls (104) ist.
10. System nach Anspruch 9, wobei mindestens zwei der Vielzahl des Kollimators (103) an
einer anderen Position entlang der Achse (AA) versetzt sind.
11. System nach Anspruch 1, wobei der Röhreneinsatz (101) einen zylinderförmigen Abschnitt
umfasst und der Kollimator (103) einen zylinderförmigen Abschnitt umfasst und den
zylinderförmigen Abschnitt des Röhreneinsatzes (101) umschließend angeordnet ist.
12. System nach Anspruch 1, wobei der Kollimator (103) einen zylinderförmigen Abschnitt
umfasst und die Vielzahl von Kollimierbereichen an einer Umfangsfläche des zylinderförmigen
Abschnitts des Kollimators (103) angeordnet sind.
13. System nach Anspruch 1, weiter umfassend:
einen Aktuator (301) zum Antreiben der Bewegung des Kollimators (103).
14. Einrichtung (200) zum Scannen eines Objekts von Interesse (201) mit einem Röntgenstrahl
(104), wobei die Einrichtung (200) Folgendes umfasst:
ein System zum Erzeugen und Kollimieren des Röntgenstrahls nach einem der Ansprüche
1 bis 13; und
einen Detektor (202) zum Detektieren des Röntgenstrahls (104), nachdem der Röntgenstrahl
das Objekt von Interesse (201) durchquert hat.
1. Système (100) pour générer et collimater un faisceau de rayons X (104), comprenant
:
un tube interne de tube à rayons X (101) pour générer ledit faisceau de rayons X,
ledit tube interne de tube à rayons X (101) étant un tube à vide ;
un logement de tube (102) pour contenir ledit tube interne de tube à rayons X (101),
ledit logement de tube (102) étant fabriqué à partir d'un matériau absorbant les rayons
X ; et
un collimateur (103) pour collimater ledit faisceau de rayons X (104) ;
dans lequel ledit collimateur (103) est agencé entre ledit tube interne de tube à
rayons X (101) et ledit logement de tube (102).
dans lequel ledit collimateur (103) comprend une pluralité de zones de collimation
(106), et dans lequel ledit collimateur (103) est adapté pour être mobile par rapport
au tube interne de tube à rayons X (101) de façon à sélectionner l'une de la pluralité
de zones de collimation (106) pour collimater le faisceau de rayons X,
caractérisé en ce que chacune d'au moins une de la pluralité de zones de collimation (106) comprend une
pluralité d'ouvertures binaires (109, 111), dans lequel lesdites ouvertures binaires
(109, 111) ont une densité dans une région centrale (107) d'une zone de collimation
étant plus élevée qu'au niveau des régions de bordure (108) de la zone de collimation.
2. Système selon la revendication 1, dans lequel chacune d'au moins une des zones de
collimation (106) est une ouverture complètement exempte de matériau.
3. Système selon la revendication 1, dans lequel chacune d'au moins une de la pluralité
de zones de collimation (106) comprend une pluralité de trous d'épingle (111).
4. Système selon la revendication 3, dans lequel lesdits trous d'épingle (111) ont une
densité dans une région centrale (107) d'une zone de collimation étant plus élevée
qu'au niveau des régions de bordure (108) de la zone de collimation.
5. Système selon la revendication 1, dans lequel chacune d'au moins une de la pluralité
de zones de collimation (106) comprend une pluralité de fentes (109).
6. Système selon la revendication 5, dans lequel la largeur desdites fentes (109) au
niveau d'une région centrale (112) d'une zone de collimation est plus grande qu'au
niveau des régions de bordure (113) de la zone de collimation.
7. Système selon la revendication 1, dans lequel ledit collimateur (103) est adapté pour
tourner autour d'un axe (AA) de façon à sélectionner l'une des zones de collimation
pour collimater le faisceau de rayons X (104), l'axe (AA) est perpendiculaire à une
direction d'irradiation du faisceau de rayons X (104).
8. Système selon la revendication 7, dans lequel ladite pluralité desdites zones de collimation
(106) est déplacée à la même position le long de l'axe (AA).
9. Système selon la revendication 1, dans lequel ledit collimateur (103) est adapté pour
effectuer une translation le long d'un axe (AA) dudit tube interne de tube à rayons
X (101) de façon à sélectionner l'une des zones de collimation pour collimater le
faisceau de rayons X (104), l'axe (AA) est perpendiculaire à une direction d'irradiation
du faisceau de rayons X (104).
10. Système selon la revendication 9, dans lequel au moins deux de ladite pluralité dudit
collimateur (103) sont déplacés à une position différente le long de l'axe (AA).
11. Système selon la revendication 1, dans lequel le tube interne de tube (101) comprend
une partie de forme cylindrique, et le collimateur (103) comprend une partie de forme
cylindrique et est agencé entourant la partie de forme cylindrique du tube interne
de tube (101).
12. Système selon la revendication 1, dans lequel ledit collimateur (103) comprend une
partie de forme cylindrique et la pluralité de zones de collimation sont agencées
au niveau d'une surface circonférentielle de la partie de forme cylindrique du collimateur
(103).
13. Système selon la revendication 1, comprenant en outre :
un actionneur (301) pour commander le mouvement dudit collimateur (103).
14. Appareil (200) pour balayer un objet d'intérêt (201) avec un faisceau de rayons X
(104), ledit appareil (200) comprenant :
un système pour générer et collimater le faisceau de rayons X selon l'une quelconque
des revendications 1 à 13 ; et
un détecteur (202) pour détecter ledit faisceau de rayons X (104) après que ledit
faisceau de rayons X a traversé l'objet d'intérêt (201).